Surface analysis of NdyFe(86-y-x)B14Mx (M=Ti, Nb) ribbons with XPS technique using synchrotron radiation

BILOVOL V, FERRARI S, PAMPILLO L, PAGNOLA M, SACCONE F

Simposio; At the Frontiers of Condensed Matter VI: Surface and Interface Properties and Engineering; 2012

CAC

Nd-Fe-B ferromagnets with low concentrations of Nd have attracted technological interest in recent years due to their magnetic properties such as high remanence and energy product. Low concentration of Nd and the use of refractory elements minimize the risk of oxidation and allow controlling the nanostructure in the solidification process and subsequent thermal treatments. Two systems of NdyFe(86-y-x)B14Mx (x=2, 4; y=7,8; M=Ti, Nb) were prepared by melt-spinning. Amorphous ribbons were submitted to thermal treatments at 700°C (crystalline) for 20 min. The surfaces of as-quenched and annealed ribbons were explored with X-ray photoelectron spectroscopy (XPS) using synchrotron radiation (LNLS, Campinas) with major emphasis on the additive elements. For each system the additives on the surface of the ribbons were found in both metallic and oxidized state. For titanium series, it was noted that the samples thermally treated have higher Ti0 content than the observed for the as quenched ones. On the other hand, for niobium series, the samples with Nb=2 and Nd=8 (both as quenched and treated) are the less oxidized ones.